The present invention relates to a method, apparatus, program and system for migrating a NAS system.
A storage apparatus as represented by a disk array apparatus logically partitions the storage area of disk devices in the storage apparatus and provides the partitioned storage areas to a host computer as volumes. This kind of storage apparatus is connected to a network, and the host computer is connected to the storage apparatus via the network so as to access the volumes in a block format or a mainframe CKD format. Moreover, a NAS (Network Attached Storage) apparatus is known as one means for providing volume access in a file format to the host computer via the network. In a NAS apparatus, an OS (Operating System) and a file system are operated to retain information concerning the files and directories stored in the respective volumes provided by the storage apparatus, and implement the input and output of files according to a request from the host computer.
If there is performance deterioration or capacity shortage in this kind of NAS apparatus, a method of migrating data of the existing NAS apparatus to the new NAS apparatus to continue the operation may be considered.
As a conventional migration method of a storage apparatus, disclosed is a method of enabling access from the storage apparatus to be newly installed to the existing storage apparatus, and the newly installed storage apparatus processing a block access request from the host computer while migrating block data from the existing storage apparatus (Japanese Patent Laid-Open Publication No. 2000-187608).